Incandescent lamp



Aug. 30, 1932. c. RAVE mcANDEscENT LAMP Filed Aug. 9. 195o UWM 6,4554# R41/E @31, Ama@ M 5o i ir these Patented Aug. 3e, 1932 cansan Raye.. or LUCKENWALDE; GERMANY 'A INeANnEscENT LAMP lubrication melangiste, 1950, semi ivo. 474,186, and' i Germany' Augusta, 19271 n `This` invention relatesf tof incandescent lamps!" and more particularly to lamps havng screw ferrules or caps`of insulating ymateria-l.` d' H 1195 y "Itsf pri-maryobject iste produce an irn-` proved lamp ofthis type Which Will eiiect a reli-ableconnection ofthe bulb; with the Vscrew :terrule'f ToL this end I secure an annular member et i i metal to the bulb of the lamp', and- Inount the `insu-ating terrule on this member. Screw `ferrules of insulating material are oct courseold, buthave never been adopted because they could not be secured satisfac` f5 terily' `and" permanently `to the bulb by the usua'lcement, and because heat stresses-i occurred which damaged the errule, or the ferrules Wereagain resorted to which are 20 readilycernented to the bulb` and Vare Anot berwlnchfmay be a ring, cylinder or sleeve, '..f'nenthe1 like,` is cementedlto the bulb in' the usual manner' and?V aordsa base for secur- 1 ingythe insulating screw terrulen` Onlythe zin tal rnemberlis subjected to high 1 tempera# T WhenIY therlamp is burning. j This be;`

" loingthe case, lsof that the insulating ferrule is not similarly heated, the "selection `ot i materiailfor the same is not limited by teml pe'ratureconsiderations; 1 The ferlrnle may Y furthermore be comparatively Weak as the 35 strength ot theconnection is provided by the `11)dications concerning the characteristics of the lamps,` such@ a-sfyoltage,v candlewpowerg eteqhave been stamped' or" etched on thefermile,u or'elsefonv the bulb. Such indications are usually very small or faint and difficult `45 to? read, so that `itfis necessary tof handle "l thelarnp tor'nspection. Obyiouslyyza lamp Ain ai screw socket must be unscrewed from the@` socket topermit areading of its indicationsz-- d y inconveniencesV are eliminated by using insulating ferules oi various colours to indicate the. properties of the lamps.' With c'a-psof this the' characteristics of the lamp,` such'as thel voltage, Wattage, candle power,A etc.,-` may be determined at a distance and Without unscrewing the lamp from its socket.v

I may additionally provide a flange on the insulating ferrule"V to abut against a Corresponding' flange on the socket, and also a' packing Washer inserted between the two tlan-gesLto--pretec't-the lamp from moisture, gas', etc.`

In the accompanying drawing, three types of me'nibersA and ferr'ules are illustrated by Way of example;-

Fig. l thereof sa sectionof a short -an- IiularV member having-hooked `mea-ns for holdngltheterrule. i Fig. 2 i's' afsection ot along threaded annuil'arV member Whicllr` is bentfover at the upper end for' hol'd 'r1, ;;k the err'ule, and

Fig` 3isf a'fsection showing. a lamp socket combir'iedV With a member' and errule as shown Filg. 1,-but With'va flange on the errul'e.` Y'

the several viewslwdenotes the bulb rule and' 13 the central-contact cap or tip.

Referring` lirst to= Figa 1l,- an annular `inember in the form of a cylinder 2" is'shown secured to a Seaton' the upper end ot thebulb l in this `instance by' a; tapering lower end restingthereon Wilth a layer ot cement represented at 3 between'. Tab-'portions l and 5 of' sali'di member orr cylinder extend upwardly through slots' a'ndf' 8 in the: ferrule 6 at opposite' sid'esi TheI centralecontact cap 13 is secured( on* 'the' top of th'ef ferr`ul'e,` While vthe Wire or Wires 20" ser've to supply `the lamp filaments (not shown) `With current.

A After the'` cylinder 2 has been secured on the bulb' 1,: the insulating-threaded' ferrule 6 is ttedl-thereover With said 'tab-portions 4 and 4-projecting upwardly through its slots 7,:and8 as the tafbtportion e appearsin Fig;V l. These tab-portions are7 theni bent down` Wardly over the slot ed es into `recesses 9 and10 inthe ferruleras tie tab-portion 5 is represented iniFi'g.-fl,isolthat the ferrule will 69 Fig; 3, is always exposed toview so thatthe be held against axial and radial displacement on the cylinder 2. When the lamp is `screwed into the socket (not shown) the endsv of the tab-portionsbear against the threads of the socket to effect a good contact.

Referring now to Fig. 2, a cylinder 12 corresponding to that above described but not equipped with tabs is shown vvithportionsll bent or doubled over at 'its upper Aend With the upper end of the ferrule Within the bend.` Said ferrule intbis instanceis threadedjon Vboth the outer and inner sides.

The top vof the ferrule may as shown be madeas arseparate part lll which isscrevved into the inner thread indicated at 15J rlkhe insulating ferrule 6,- Which may consist of aV plastic substance Vsuch as paper,

cellulose,gartiiicial rosinor the like, and the cylinder jyvhichwfastens to the bulb are pre- Y ferably connected with each` othertfirst and e thenthreaded K (including/the bent portions l11)V before thercylinder is j isecured onthe bulb 1.

The ferrule affords'l excellent yprotection against touching contacts, as the 4contacting parts are arranged only in the upper end of theY errule andA make contact with V.other parts under voltage only after having been completely ,concealed in the holder socket.

Onlythe lower end Vof the ferrule ,projects from the'socket and it therefore prevents any touching of parts carrying current.

" Referring now'gto Fig. 3, ftheferrule and the cylinder (not showing) :are-,thesame as ,inV VFig. 1, except that theferrule is yprovided with a flange 16 at itslowerend. A These parts are shown screwed into a threadedSOQket lvvithinl the usual shieldor holder 17j-.preferably of insulatingy material, Aagainst the' end of which said flange '16bit the ferrule is pressed. A packing Washer 18A may v,be placedk between lthemfor protection against moisture or gas.V ZrEhe holderY memberinay have or connect Withn a suspension eye 21 at its upper end and current conductorivvires Y 22VV 'for supplying the currentV mayfrull through openings at its sides. i I

lThisV holder or shield in the described construction prevents moisture or gas admission and atfthe same time relievesfthe delicate bulbfof thrust from the pressurel exerted on theA Washer '18. If the insulating ferrule is made of a bad conductorof beau-the Washer 18 may bemade of rubber, a material which cannot be used With metal lf'errules as they becometoohot.' v n. "Y Y Y As mentioned, the ferrule 'may be colcured variously, as and for they purpose described. VIts'lovver end, or the flange. 16 in characteristicsbf the lamp may be readily Vascertained atA aglance.' Y

' I claim:

- f1. In anV incandescent Vlamp including bulb, a screW-ferrule.,base comprising ananf Vend of the nular metal member having one end secured on the lamp bulb and an opposite end ex-V e Y,

tension portion, and a threaded ferrule of an insulationV material iitted over said member with theextension portion of the formerv bent over and down thereon providing current conductors Vbearing against the wall of theu'holder socketintoWhich the/,same may be screwed.l y g 2. A screweferrule base for incandescent lamps, comprisinganiannular metal member secured on the neck of the lamp, and a vthreaded insulation ferrule fitted overV said member with a flexible portionof'the former "hooked over and down'npontlie same for holding it in'place thereon and providing a current Vconductor vbearing against the Wall portions at its other end adapted tozbending over, and a threaded ferrule-of.insulation ymaterial fitted oversaid member With-one end bearing thereon against the lamp and with said extension portionsof theI member bentdovvnWardly` thereover at the .otherfend f so as `to holdfit inplace and provide current Y c Y e conductors bearing against the Walls of the socket member into which screwed. Y i

f 4, Inarfigincandescent lamp,'ascreW-fe rule base comprising an annular `metal :member secured o n the lampbulb and having axially extendedportions adapted tobending, and a threaded ferrule of insulation material lfitted over `said member and havingmslot openings icc 1 throughwhich said'axially extendedlportions ofthe member are passed andbentdoWIl'r Wardly, thereon for holding it in l e neilandY providing Ag current y against the' Walls of the socket into Which the vsame is' screwed. '-j 5.3111 an incandescent lamp,'a'screW- fefrfV conductors bearing jrule base for securingin-ajholder socket, 'comp risin'gv an annularv threaded, metal. member lsecured on the neck ofthe lamp and having axially extended portions Yadapted to bendeV ing over, and.- a threaded ferrule of insulation material appliedover said member with vthe axially extended portions of thegforiner bent over and partially down upony thesame flush With the threading of its outer surface for holdingy it secureand providingv contact against the Wall of thefsocketintor which screwed.

` 16., VAnY incan,4 escent lamp havingjan insulae vtion scre-w-ferrule for securing'in a holder socket, comprising. an annular-'metal collaif".V

securedon the neck ofrthelamp bulbV and having axially extended tab-portions adapted tol .bending over, and a threaded ferrule of insulation material tted over said member with said tab-portions of the member eX- tending through slots therein and bent doWn Wardly over the outer surface thereof into recesses so as to hold it in 'place and provid ing contacts bearing against the inner Wall of the socket into Which the same is screwed; said verrule carrying a center Contact cap on its outermost end.

l@ `7. In an incandescent lamp including a bulb, an insulated screw-ferrule base there? on,comprising an annular metal member sea cured on said bulb and a threaded errule of insulating material fitted over said member With tap-portions of the same bent over and down thereon for holding it in place and providing current conductors bearing against the Walls ofthe holder socket into which `screw-ed.

2e 8. In an incandescent lamp including a bulb, an insulating screw-ferrule base thereon comprising an annular metal member cei mented on said bulb, a threaded insulating ferrule fitted over said member and a ieXible extension of said member hooked over an edge of the ferrule to hold it in place there- 9. A, screW-ferrule base for an inoandes cent lamp, comprising an annular metal 3G member `secured on the lamp bulb and a threaded insulating ferrule tted over said member with a flexible portion of the former x hooked over and down upon the same for holding it in place thereon and providing a current conductor bearing against the Wall of a socket into which screwed.

In testimony whereof I affix my signature.

` CAESAR RAVE. 

